duncan01

The 24's are in with a 190lph and have an adjustable regulator set at 39psi vac line off.

dawson1112

The problem you are having with the car seeming like it wants to die when you are coming to a stop could be a broken baffle in the fuel tank, but I think it has more to do with the maf conversion than anything else. The old speed density cars used a manifold absolute pressure sensor and there was really no need to have a vehicle speed sensor because the ecm could look at the MAP sensor and see the sudden rise in vacuum or drop in pressure. When you release the throttle quick you suddenly stop a large flow of air entering the manifold, this creates a pressure wave that the ecm would ordinarily see with the MAP sensor. with the maf the vehicle looks at vehicle speed sensor.
I am only saying this because it has been reported by some pple that have done the maf conversion with out the vss signal to the ecm that they experience stalling problems upon coming to a stop . I don't know how the maf conversion was done to your car but if the vss signal was skipped because the trans didn't have the vss in it , this could very well be your issue . Some of the older speed density cars that had cruise control already had a vss in the trans to allow for cruise control, but a lot pple don't know that in the maf cars the ecm also uses this to maintain a certain rpm between shifting and also to keep idle up during a rapid release of the throttle while coming to a stop.

so if your car was not equipped with cruise control it didn't have the vss.

duncan01

that I couldnt tell you, but all I did was swap heads and never had this problem before this.

dawson1112

Im not ruling out the maf conversion , because if you went from the stock e7s to the gt40x heads your air flow is a lot higher relulting in a much greater change in pressure from open throttle to closed, but we'll assume it was a correct conversion for the moment .

Your tps is set to .94v correct ?
Try to bump the voltage up to around .98 or .99 on the tps and repeat the base Idle reset. I had to tweak mine till I found a spot that got me where I wanted to be . When I have mine at .98 the idle stays really high inbetween gears and coming to a stop it would take about 10 seconds or so to idle back down to where it should be. As I backed the tps voltage down a bit at a time I noticed it got better and better. Finnally at .92 it idles right where it should when depressing clutch and shifting or stopping.

Any time you change that air flow things will need to be retweaked and played with to get it where you can be happy with it.

With the lopey cam , higher flowing heads and intake , there is only so much tweaking you can do to the car with a screw driver , until you have to take it and have it dyno tuned.

Also sometimes you just have to drive it for a while for the adaptive learning of the ecm to correct it self .

duncan01

I will try and bump the tps up. Also, I have seen agrumentitive threads on how the fine increments of adjustment for tps are non effective as long as its within the range. I do agree with what your saying and can see both sides I hope it works. I drove it in to work today and it seems to be doing better the more I drive it.

mjr46

setting tps to anywhere in .7 to 1.1 vdc is acceptable once you understand the ecm logic laid out in the GUFB document. picking a certain voltage and saying it needs to be there is a myth even though many claim it works. Here is a link to a good discussion on the matter, if you can't see it, sign up at sbftech :

http://sbftech.com/index.php/topic,13644.0.html

The logic described below considers the current position of the throttle
and compares its value to the RATCH, Closed Throttle, plus the change in
throttle position from the last setting. If both flip-flops in the logic
clear, then Part Throttle is set.


OVERVIEW
The throttle mode scheduler is used to determine what engine operating
region is currently extant. The variable APT (At Part Throttle flag) is used
to indicate throttle mode and is assigned the following values:
Throttle Mode APT
------------------ ---
CLOSED THROTTLE -1
PART THROTTLE 0
WIDE OPEN THROTTLE 1
The value of APT is determined by the logic shown on the following page.
Briefly, throttle angle breakpoints, in terms of counts, are used to define
the CLOSED/PART_THROTTLE and PART/WIDE_OPEN_THROTTLE transitions. Hysteresis
is incorporated in both breakpoints to prevent jitter between modes.
The variable RATCH is the output of a ratchet algorithm which continuously
seeks the minimum throttle angle corresponding to a CLOSED THROTTLE position.
This alleviates the necessity to set the throttle position sensor at an
absolute position and compensates for system changes and differences between
vehicles. The ratchet algorithm uses filtered throttle position for the
determination of RATCH.
A more detailed explanation of the throttle position ratchets and throttle

duncan01

Oh man thats painful. I hope you understand what you just wrote lol

dawson1112

lol He does..

Mike T

Keep driving it, I believe the ECU will relearn without you doing any adjusting. Mine was doing the exact same thing, pretty regularly and now it doesn't happen anymore.

dawson1112

I agree , it takes a bit of time for the adaptive learning to dial itself in.